CODEWITHSUNDEEP
cobolzos
Maxcc0
Maxcc0

Reputation: 49

Re-compiling the old COBOL source codes with the latest compiler

What are the possible issues which we may encounter while re-compiling old COBOL(V4) source codes with the latest compiler (COBOL V6). Can someone list out few of them? Thanks.

Upvotes: 0

Views: 714

Answers (1)

Ka Lam
Ka Lam

Reputation: 381

Start with reading these 2 docs

In the migration guide, "Migration recommendations to Enterprise COBOL V5 and V6" https://www.ibm.com/support/knowledgecenter/en/SS6SG3_6.2.0/com.ibm.cobol62.ent.doc/migrate/igymch1600rec.html

Whitepaper "Migrating to the COBOL V5 and V6 compiler is different!" http://www-01.ibm.com/support/docview.wss?uid=swg27039560

Environment issues such as the use of PRELINKER (not supported in V5+); requirement of PDSE; V5+ executable are larger.

The typical COBOL programming issue is bad data processed by V4 COBOL compiler generated program used to be more tolerated; V6 compiler use newer instructions that don't tolerate bad data. What is bad data? For example, a ZONE DECIMAL number that has invalid zone nibbles; a PACK DECIMAL number where the sign nibble is wrong.

Another area of issue comes from COBOL coding error that lay dormant for years, such as memory corruption, but when the memory layout of (not grouped) data item may not be the same as V4, the memory corruption cause program logic to change and expose the bug.

Upvotes: 9

Related Questions